The National Research Council (NRC), in its 1992 report, Restoration of Aquatic Ecosystems, defined restoration as the "return of an ecosystem to a close approximation of its condition prior to disturbance." That report also states, "The term restoration means the reestablishment of predisturbance aquatic functions and related physical, chemical and biological characteristics (Cairns, 1988; Magnuson et. al., 1980; Lewis, 1989). Restoration is ... a holistic process not achieved through the isolated manipulation of individual elements.
The objective is to emulate a natural, self-regulating system that is integrated ecologically with the landscape in which it occurs. Often, restoration requires one or more of the following processes: reconstruction of antecedent physical conditions, chemical adjustment of the soil and water; and biological manipulation, including the reintroduction of absent native flora and fauna..."
According to the US EPA, the ecological and societal benefits of river corridor and wetlands restoration are substantial:
- Rivers transport water, sediment, and nutrients from the land to the sea, play an important role in building deltas and beaches, and regulate the salinity and fertility of estuaries and coastal zones. Rivers serve as corridors for migratory birds and fish, and provide habitat to many unique species of plants and animals, including federally endangered and threatened aquatic species. According to the 1985 National Survey of Fishing, Hunting, and Wildlife -Associated Recreation (U.S. DOI, Fish and Wildlife Service, 1988), 38.4 million fishermen spent $17.8 billion for non-Great Lakes freshwater fishing in 1985, with 45 percent of reported anglers fishing in rivers and streams.
- Wetlands provide food, protection from predators, and other vital habitat factors for many of the nation's fish and wildlife species, including endangered and threatened species. In addition, wetland ecotypes have economic value associated with recreational, commercial, and subsistence use of fish and wildlife resources and they remove pollutants from overland flows before they reach our lakes, rivers and bays.
- Wetlands intercept storm runoff and release floodwaters gradually to downstream systems. When wetlands are converted to systems without water retention capacity, downstream flooding problems increase.
Rio Salado Habitat Restoration Project
US Environmental Protection Agency
US Army Corps of Engineers